1. Field of the Invention
The present invention relates to a magneto-optical recording/reproducing method for recording and/or reproducing information by applying a magnetic field modulated according to information from a magnetic head while radiating a laser beam onto a disk-shaped magneto-optical recording medium.
2. Related Background Art
A conventional drive apparatus for executing a magneto-optical recording/reproducing method has an arrangement, as shown in FIGS. 1A and 1B. The drive apparatus shown in FIGS. 1A and 1B comprises a flying magnetic head 101 for applying a modulated magnetic field, a holding member 102 for holding the flying magnetic head, a positioning member 103 for regulating the loading position of the flying magnetic head to a magneto-optical disk, a bearing 104 for holding the flying magnetic head 101 in an unload state, and allowing a seek operation of the holding member 102, a guide shaft 105 for guiding the bearing in the seek direction, a stopper 106 for positioning the holding member 102 by abutting it against the positioning member 103, an optical head 107 for radiating and receiving a laser beam to and from a magneto-optical disk so as to record/reproduce information, a linear motor coil 108 for performing a seek operation of the optical head 107 in the radial direction of the disk, an actuator 109 for focusing a laser beam radiated from the optical head 107 on the recording surface of the recording medium, and moving the laser beam in the tracking direction, and a disk cartridge 110 for protecting and storing the recording medium (a disk 110a in FIGS. 1A and 1B).
A write protect switch 110b which slides in a groove is provided to the cartridge. The apparatus also comprises a spindle motor 111 for rotating the magneto-optical disk 110a, a write protect detection means 112 for mechanically detecting the position of the groove of the write protect switch 110b provided to the disk cartridge 110, a guide rail 113 for guiding the optical head in the seek direction, an optical detection means 114 for receiving and photoelectrically converting an information signal based on a laser beam from the optical head 107, and a control circuit 115 for controlling a drive circuit 116. The drive circuit 116 drives a drive means 117 on the basis of signals from the optical detection means 114 and the write protect switch 112 so as to drive the linear motor 108 and the actuator 109 and to move the guide shaft 105 vertically.
In the prior art, as shown in FIG. 2, the disk cartridge 110 is loaded, the spindle motor 111 is started, auto-focus servo control and auto-tracking servo control of the magneto-optical disk 110a are performed by the actuator 109 mounted on the optical head 107, and the control track of the magneto-optical disk 110a is read to discriminate whether the magneto-optical disk is the following disk A or B:
Disk A: magnetic field modulation magneto-optical disk;
Disk B: optical modulation magneto-optical disk.
When it is determined that the disk 110a is the disk B, the flying magnetic head 101 is not loaded, and a standby state is set. On the other hand, when it is determined that the disk 110a is the disk A, a disk write protect mode is further checked. If the write protect mode is ON, the flying magnetic head 101 is not loaded, and a standby state is set. However, if the write protect mode is OFF, the drive means 117 is enabled to load the flying magnetic head 101.
In the prior art, since the flying magnetic head 101 is loaded under the auto-focus servo control and auto-tracking servo control, when the state shown in FIG. 1A is switched to the state shown in FIG. 1B, i.e., when the flying magnetic head 101 is loaded with respect to the disk 110a, it may often give a disturbance, and the servo control may fail. When the servo control fails, a laser beam from the optical head 107 is radiated on a track considerably separated from a control track (standby position) for a target track, and the target control track (standby position) must be accessed again. When the servo control completely fails (when both the auto-focus servo control and auto-tracking servo control fail), auto-focus servo control and auto-tracking servo control must be performed again, and the control track as the target track must be accessed. Since a large disturbance is input to a servo control system, an excessive current is temporarily supplied to the actuator 109.